interface TopBarItemPluginInterface

interface TopBarItemPluginInterface {
    
    /**
     * Returns the translated plugin label.
     *
     * @return string|\Stringable
     *   The translated plugin label.
     */
    public function label() : string|\Stringable;
    
    /**
     * Returns the plugin region.
     *
     * @return \Drupal\navigation\TopBarRegion
     *   The plugin region.
     */
    public function region() : TopBarRegion;
    
    /**
     * Builds and returns the renderable array for this top bar item plugin.
     *
     * If a top bar item should not be rendered because it has no content, then
     * this method must also ensure to return no content: it must then only return
     * an empty array, or an empty array with #cache set (with cacheability
     * metadata indicating the circumstances for it being empty).
     *
     * @return array
     *   A renderable array representing the content of the top bar item.
     */
    public function build();

}